U.S. patent application number 11/359061 was filed with the patent office on 2007-08-23 for system and method for handling call redirection and multi call destination failures.
This patent application is currently assigned to Lucent Technologies Inc.. Invention is credited to Ruth Schaefer Gayde, Suzann Hua, Todd Cartwright Morgan, John Richard Rosenberg.
Application Number | 20070195752 11/359061 |
Document ID | / |
Family ID | 38428096 |
Filed Date | 2007-08-23 |
United States Patent
Application |
20070195752 |
Kind Code |
A1 |
Gayde; Ruth Schaefer ; et
al. |
August 23, 2007 |
System and method for handling call redirection and multi call
destination failures
Abstract
A system and method for providing Call
Forwarding/Multi-Destination Call Redirection services that include
notifying the subscriber/owner of a call leg creation failure and
taking corrective action to prevent future failures. The failure
can be detected at a Far End network node and communicated to a
Detection node which communicates with a Resolver node for taking
corrective action.
Inventors: |
Gayde; Ruth Schaefer;
(Naperville, IL) ; Hua; Suzann; (Lisle, IL)
; Morgan; Todd Cartwright; (Oak Park, IL) ;
Rosenberg; John Richard; (Elmhurst, IL) |
Correspondence
Address: |
FAY SHARPE/LUCENT
1100 SUPERIOR AVE
SEVENTH FLOOR
CLEVELAND
OH
44114
US
|
Assignee: |
Lucent Technologies Inc.
|
Family ID: |
38428096 |
Appl. No.: |
11/359061 |
Filed: |
February 22, 2006 |
Current U.S.
Class: |
370/352 ;
370/216 |
Current CPC
Class: |
H04M 3/54 20130101; H04M
7/0042 20130101; H04M 3/42153 20130101; H04M 3/465 20130101; H04L
12/66 20130101; H04M 3/46 20130101 |
Class at
Publication: |
370/352 ;
370/216 |
International
Class: |
H04J 3/14 20060101
H04J003/14; H04L 12/66 20060101 H04L012/66; H04J 1/16 20060101
H04J001/16 |
Claims
1. A method of call control in a communications network comprising:
determining that a Call Redirection/Multi-Call Destination (CR/MCD)
call leg for a subscriber cannot be established at a Far End
Switch; sending one or more messages from the Far End Switch to a
Detector indicating that the CR/MCD call leg cannot be established
and the reason the CR/MCD cannot be established; and performing an
Action based on the failure to establish the CR/MCD call leg.
2. The method defined in claim 1 wherein the communications network
includes at least one of a circuit switched network, a packet
network, a packet network, an Internet Protocol Multimedia
Subsystem (IMS) network, and an Internet Protocol network.
3. The method defined in claim 1 wherein the Action includes
notifying a subscriber/owner that a CR/MCD call leg cannot be
established.
4. The method defined in claim 1 wherein the Action includes
notifying a subscriber/owner of the reason that a CR/MCD call leg
cannot be established.
5. The method defined in claim 1 wherein the Action includes
notifying a subscriber/owner of a different destination number for
establishing the failed CR/MCD call leg.
6. The method defined in claim 1 wherein the CR/MCD call leg is
part of a Call Forwarding call operation.
7. The method defined in claim 1 wherein the CR/MCD call leg is
part of a Simultaneous Ringing call operation.
8. The method defined in claim 1 wherein the CR/MCD call leg is
part of a Multi-Line Hunt Group call operation.
9. The method defined in claim 1 wherein the CR/MCD call leg is
part of a Flexible Alerting call operation and the step of
performing an Action includes at least one of notifying the
Flexible Alerting Pilot that the CR/MCD call leg cannot be
established and notifying the Flexible Alerting Pilot of the reason
that the CR/MCD call leg cannot be established.
10. The method defined in claim 1 wherein the Detector is an
Originating Call Control Element.
11. A system for performing Call Redirection/Multi-Call Destination
(CR/MCD) in a communications network comprising: a Far End switch
including means for determining that a CR/MCD call leg for a
subscriber cannot be established and means for communicating with a
Network Element that the CR/MCD call leg cannot be established and
the reason the CR/MCD call leg cannot be established; a Detector
located- remotely from the Far End Switch including means for
communicating with the Far End switch to determine that the CR/MCD
call leg cannot be established and the reason that the CR/MCD call
leg cannot be established and means for notifying a network element
that a CR/MCD call leg for the subscriber cannot be established;
and a Resolving Network Element including means for communicating
with the Detector for determining that a CR/MCD call leg cannot be
established and the reason that the CR/MCD call leg cannot be
established and means for performing an Action based on the failure
to establish the CR/MCD call leg.
12. The system defined in claim 11 wherein the Detector is an
Originating Call Control Element.
13. The system defined in claim 11 wherein the Action includes
notifying a subscriber/owner that a CR/MCD call leg cannot be
established.
14. The system defined in claim 11 wherein the Action includes
notifying a subscriber/owner of the reason that a CR/MCD call leg
cannot be established.
15. The system defined in claim 11 wherein the Action includes
notifying a subscriber/owner of a different destination number for
establishing the failed CR/MCD call leg.
16. The system defined in claim 11 wherein the CR/MCD call leg is
part of a Flexible Alerting call operation and the Action includes
at least one of notifying the Flexible Alerting Pilot that a CR/MCD
call leg cannot be established and notifying the Flexible Alerting
Pilot of the reason that a CR/MCD call leg cannot be
established.
17. The system defined in claim 11 wherein the CR/MCD call leg is
part of a Simultaneous Ringing call operation.
18. The system defined in claim 11 wherein the CR/MCD call leg is
part of a Multi-Line Hunt Group call operation.
19. The system defined in claim 11 wherein the CR/MCD call leg is
part of a Call Forwarding call operation.
20. The method defined in claim 11 wherein the communications
network includes at least one of a circuit switched network, a
packet network, an Internet Protocol Multimedia Subsystem (IMS)
network, and an Internet Protocol network.
Description
BACKGROUND OF THE INVENTION
[0001] This invention relates to a system and method for providing
call redirection and/or multi call destination services and more
particularly to a system and method for providing suitable actions
based on call leg creation failures occurring during these service
operations.
[0002] While the invention is particularly directed to the art of
telecommunications networks including wireless and wireline
networks as well as packet data networks, and will be thus
described with specific reference thereto, it will be appreciated
that the invention may have usefulness in other fields and
applications including .
[0003] Today, when a user registers a number for call forwarding,
also known as call redirection, or as part of a multi destination
call with the network, such as a registration of a Call Forwarding
Forward-To Number (FTN), the network may not validate whether the
number used for the redirection is a valid destination. If the
number used for redirection turns out to be bad, such as a
disconnected number, there is no automated mechanism to correct the
problem to prevent further occurrences. There is also no automated
mechanism to notify the served user, that is the user who
registered the bad number, of the error. Consequently, this problem
will persist for this user until perhaps he is notified by a person
who has tried unsuccessfully to communicate with him in this
manner.
[0004] The context for bad numbers for call redirection and/or
multi call destination calls includes not only call forwarding, but
also such services as Flexible Alerting, Simultaneous Ringing,
Multi-Line Hunt Group, Sequential Ringing, and Series Completion
Service. For all of these services, the served user may provision
one or more destination numbers and is not involved at invocation
time and thus cannot receive immediate notification when a
destination number is bad.
[0005] The present invention contemplates a new and improved system
and method that resolves the above-referenced difficulties and
others.
SUMMARY OF THE INVENTION
[0006] A system and method for providing Call Redirection and/or
Multi Call Destination services that can include performing a
corrective Action and/or notifying the subscriber/owner of a call
leg creation failure and providing them further information which
can include the reason for the failure.
[0007] In one aspect of the invention, the method includes
determining that a Call Redirection/Multi Call Destination (CR/MCD)
call leg for a subscriber cannot be established at a Far End
switch, sending one or more messages from the Far End Switch to a
Detector indicating that the CR/MCD call leg cannot be established
and the reason the CR/MCD cannot be established, and performing an
Action based on the failure to establish the CR/MCD call leg.
[0008] In another aspect of the invention the system includes a Far
End switch including means for determining that a CR/MCD call leg
for a subscriber cannot be established and means for communicating
with a Network Element that the CR/MCD call leg cannot be
established and the reason the CR/MCD call leg cannot be
established, a Detector located remotely from the Far End Switch
including means for communicating with the Far End switch to
determine that the CR/MCD call leg cannot be established and the
reason that the CR/MCD call leg cannot be established and means for
notifying a network element that a CR/MCD call leg for the
subscriber cannot be established, and a Resolving Network Element
including means for communicating with the Detector for determining
that CR/MCD call leg cannot be established and the reason that the
CR/MCD call leg cannot be established and means for performing an
Action based on the failure to establish the CR/MCD call leg.
[0009] Further scope of the applicability of the present invention
will become apparent from the detailed description provided below.
It should be understood, however, that the detailed description and
specific examples, while indicating preferred embodiments of the
invention, are given by way of illustration only, since various
changes and modifications within the spirit and scope of the
invention will become apparent to those skilled in the art.
DESCRIPTION OF THE DRAWINGS
[0010] The present invention exists in the construction,
arrangement, and combination of the various parts of the device,
and steps of the method, whereby the objects contemplated are
attained as hereinafter more fully set forth, specifically pointed
out in the claims, and illustrated in the accompanying drawings in
which:
[0011] FIG. 1 is a block diagram illustrating a system for handling
call redirection/multi call destination (CR/MCD) failures in
accordance with the invention;
[0012] FIG. 2 is a flow chart illustrating a method for handling
call redirection/multi call destination (CR/MCD) failures in
accordance with the invention;
[0013] FIG. 3 is a block diagram illustrating an example of a CDMA
system for handling Call Redirection failures in accordance with
the invention;
[0014] FIG. 4 is a call flow diagram illustrating the messaging
provided by the system illustrated in FIG. 3 for Call
Redirection;
[0015] FIG. 5 is a call flow diagram illustrating the messaging
provided by the system illustrated in FIG. 3 for Flexible
Alerting;
[0016] FIG. 6 is a block diagram illustrating an example of an IMS
system for handling Call Redirection failures in accordance with
the invention; and
[0017] FIG. 7 is a call flow diagram illustrating the messaging
provided by the system illustrated in FIG. 3 for Call
Redirection.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0018] Referring now to the drawings wherein the showings are for
purposes of illustrating the preferred embodiments of the invention
only and not for purposes of limiting same. In FIG. 1, a system
shown generally at 10, for performing Call Redirection and/or Multi
Call Destination (CR/MCD) call services in a communications network
for voice calls made by a calling party A to a called party B which
are forwarded or redirected to one or more parties C, D, E, etc.
CR/MCD calls as pertaining the invention described herein, can
include services including, but are not limited to, call
forwarding, call redirection, flexible alerting, simultaneous
ringing, and multi-line hunt groups, among others.
[0019] For the examples provided herein, party B, for which calls
are being forwarded or redirected, can be referred to as a
subscriber, such as a subscriber to the CR/MCD services described
herein, or the owner of such data that may be required to perform
these services. The system 10 includes network elements of suitable
construction using suitable protocols so as to be applicable to
cellular telecommunications networks, landline telecommunications
networks, circuit switched communications networks, packet-based
communications networks, Internet Protocol (IP) communications
networks such as those suitable for Voice Over Internet Protocol
(VOIP) calls, and Internet Protocol Multimedia Subsystem (IMS)
communications networks. FIG. 2 illustrates the general method of
operation, as shown generally at 200, of the system 10 described
herein.
[0020] The system 10 includes a Detector 12 for detecting a failure
in the establishment of a CR/MCD call leg 13, also referred to as a
CR/MCD call leg creation failure, during a CR/MCD operation as
shown at step 202. If this failure is not detected, normal call
processing occurs at 204. An example of a CR/MCD call leg includes
the call leg to the forwarded or redirected destination, as
represented herein by C. C can be a phone, landline or mobile
terminal, or other apparatus for receiving calls such as a VOIP
capable device, etc. The Detector 12 can also determine the reason
for the failure, such as for example, the forwarded/redirected
destination number is out of service or disconnected, or this
number has been changed, or the CR/MCD information includes a
vacant code or unassigned number, etc. The Detector 12 can be a
switch, a Mobile Switching Center (MSC), an Application Server
(AS), or some combination thereof, among others.
[0021] The system 10 can also include a Far End Switch 18
responsible for establishing the CR/MCD call leg 13 to the
forwarded/redirected destination, C in most of the examples
provided herein. The Far End Switch 18 typically establishes the
CR/MCD call leg to a local destination, or a destination assigned
to the switch, such as C's phone.
[0022] The Far End Switch 18 includes means for determining that
the CR/MCD call leg 13 cannot be established, that is to say that
the CR/MCD call leg creation has failed. The Far End Switch 18 also
includes means for communicating to the Detector 12 at 14 that the
CR/MCD call leg cannot be established as shown at step 206. The Far
End Switch 18, can also include means for communicating to the
Detector 12 at 16 the cause or the reason that the CR/MCD call leg
cannot be established as shown at step 208. These communications 14
and 16 can be provided using SIP or ISUP signaling, or other known
protocols employing new commands or fields, etc. for providing this
information. It should be appreciated that the separate messages
shown at 206 and 208 can be a single message.
[0023] The Detector 12 includes means for determining that the
CR/MCD call leg 13 cannot be established, that is that CR/MCD call
leg creation failed, which can include means for communicating with
the Far End Switch 18 for receiving this information. The Detector
12 can also include means for determining the reason that the
CR/MCD call leg creation failed, which can include means for
communicating with the Far End Switch 18 for receiving this
information provided as described above.
[0024] The system 10 also includes a Resolving Network Element
(RNE) 20 having means for performing one or more Actions, shown
generally at 22, based on the failure to establish the CR/MCD call
leg. As described in further detail in the examples provided
herein, the Action 22 can include notifying the subscriber of the
failure to establish the CR/MCD call leg and the reason for the
failure as shown at step 210. The notification can include sending
a message over one or more media to the subscriber B, also referred
to as the owner B, to alert them of the redirection error. One
example of such as message can include sending an SMS message
and/or email informing B that their CR/MCD number, that is the
number used to redirect their calls to C, is bad. Other examples of
notifications include sending a SIP MESSAGE directly to a
SIP-enabled user entity (device), leaving a message in a voice
mail, sending an instant message, sending notification to web
portal or other set of application servers.
[0025] The Action 22 performed by the RNE 20 based on the failure
to establish the CR/MCD call leg can also include deactivating the
bad CR/MCD number to cease initiating future CR/MCD call legs to
the affected destination as shown at 212. The Action 22 can take
place after one CR/MCD call leg failure or after reaching a
threshold including a predetermined number of failures to the same
destination, that of C in the examples provided. The RNE 20 can be
a Home Location Register (HLR) in a wireless telecommunications
network, a Service Control Point (SCP), an Application Server, or a
Switch, such as a switch in a wireline telecommunications
network.
[0026] It should be appreciated that the Detector 12 and RNE 20 can
be the same network element as shown by the dashed line 12/20.
Alternatively, the Detector 12 and RNE 20 can be different network
elements, and if different elements, the system 10 also includes
means for communicating between the Detector 12 and the RNE 20, for
informing the RNE of the CR/MCD call leg creation failure as shown
at 24 and means for communicating between the Detector and the RNE
for providing the RNE information needed to take the Actions
described herein as shown at 26. This information can include an
identification of the subscriber B and the failed CR/MCD number,
the number for reaching C, and the cause or reason for the
failure.
[0027] FIG. 3 shows an example of the system 10 described above,
which is shown generally at 310, that includes CDMA wireless
telecommunications network elements as part of a wireless network
for performing Call Forwarding in accordance with the invention.
FIG. 4 illustrates the call flow messaging sent between the network
elements of FIG. 3 for this Call Forwarding example. In the example
illustrated by FIGS. 3 and 4, calling party A calls called party B.
Called party B subscribes to Call Forwarding, as provided by B's
wireless telecommunications Service Provider, so that calls made to
B's Directory Number are forwarded to C.
[0028] In the system 310 of this example, the Detector 12 includes
an Originating Call Control Element (OCCE), and more specifically
an Originating MSC (O-MSC) 312. The O-MSC 312 is responsible for
routing CR/MCD calls made to the subscriber B to one or more other
destinations, such as for example to C.
[0029] The system 310 also includes a Far End Switch 318 for
establishing a CF call leg to C. The O-MSC 312 communicates with
the Far End Switch 318 via the PSTN 330. The system 310 also
includes B's HLR 320 functioning as the RNE 20. The system 310 also
includes an SMS Message Center 340 for sending SMS messages to B as
shall be described in further detail below.
[0030] The Originating MSC 312 receives the incoming call destined
for B by receiving an Initial Address Message (IAM) identifying B
as the destination for the call from the Public Switched Telephone
Network (PSTN) at 402. In this example, the O-MSC 312 is B's
Originating MSC which receives calls destined for B and is
responsible for routing these incoming calls to B, including
instances where B is roaming.
[0031] The O-MSC 312 attempts to route the call to B by sending a
Location Request Invoke (LOCREQ) message to B's HLR at 404. The
LOCREQ message identifies B, such as by B's DN or in some other
manner, as the called party to which the call is to be routed
to.
[0032] B's HLR 320 determines that calls made to B are to be
unconditionally call forwarded to C at 406. As a result of this
requirement, the HLR 320 retrieves a Call Forwarding
Forward-to-Number (FTN) for C.
[0033] The HLR responds to the LOCREQ of 404 with a Location
Request Return Result response (locreq) at 408 providing C's FTN
address, such as C's phone number, to the O-MSC for forwarding the
call to C.
[0034] The O-MSC 312 forwards the call to C at 410 by sending an
IAM to the appropriate Far End Switch 318 responsible for setting
up calls to C, as determined by locreq-response from 408. The IAM
includes C's address as the Called Party Number and B's address as
the Original Called Number (OCN).
[0035] As a result of C's number being recently disconnected, the
Far End Switch 318 cannot route the call to C by establishing the
call leg to C at 412, resulting in a CR/MCD call leg creation
failure. Thus, the Far End Switch 318. informs the O-MSC 312 of
this failure and the reason for this failure by sending a RELEASE
(REL) message back to the O-MSC at 414 providing this information.
The REL message can inherently indicate the CR/MCD call leg
creation failure to the O-MSC 312. The REL message can provide the
MSC with the reason for the call failure, that being C's number has
been disconnected. Further, if the number used for
forwarding/redirecting calls to C is changed to a new number,
instead of being disconnected, the Far End Switch 318 can include
the new number in the REL message or some similar message.
[0036] The O-MSC 312 receives the REL message 414 detecting the
CR/MCD call leg creation failure and the reason for this failure as
provided by the contents of the REL message at 416. The O-MSC 312
then informs the. HLR 320 by sending a Call Forward (CF) Complaint
message at 418 indicating to the HLR that there has been a CR/MCD
call leg creation failure. The CF Complaint message also includes
B's number as the called party number and C's number as the FTN,
and the reason for the CR/MCD call leg creation failure. If C's
number was changed, the CF Complaint message can include the new
number.
[0037] Because of the CF Complaint notification message of 418, the
HLR 320 deactivates Call Forwarding for B to C at 420.
[0038] Further, upon receiving the CF Complaint notification
message of 418, the HLR 320 notifies B that the CR/MCD destination
number, C's number, being used as the FTN number, is not correct
because it has been disconnected. As stated, this notification can
be provided via a text message. The HLR 320 sends an SMS Message
Delivery Point to Point (SMDPP) message to the SMS Message Center
340 at 422. The SMDPP message includes B's number as well as the
text message to be set to B notifying B that B's call forwarding to
destination C is inoperative. The message can also indicate the
reason for this, such as C's number has been disconnected, etc. The
text message is sent to B at 424. The message can also include C's
new number if C's number was changed as opposed to being
disconnected as described above.
[0039] The Call Redirection (Call Forwarding) example can include
calls forwarded more than once, that is calls forwarded from B to C
and then from C to D. In this example, C has also forwarded to D
using MSC-2. If the call leg creation to D fails because D is a bad
destination, then the failure detector for the C-to-D leg will
notify C's HLR, in a manner similar to the message at 418 above,
but not B's HLR. The ISUP REL message will propagate backward from
MSC-2 to MSC-1. Any MSC-1 that has implemented the invention will
also have the intelligence to recognize that this CR/MCD call leg
creation failure occurred during multi-hop forwarding due to
parameters in the signaling such as Original Called Number and
Redirecting Number not being equal for the multi-hop case. Further,
the MSC-1 also knows that the CR/MCD call leg creation failure
happened only on the last CR/MCD leg using MSC-2. The reason for
not propagating the CF deactivations and failure notifications all
the way backward to the O-MSC reduces any confusion that would
occur on B's part since B may not know that the call is being
forwarded from C to D.
[0040] Referring now to FIG. 5, a call flow diagram is shown
illustrating an example for a CDMA Flexible Alerting (FA) service
in which a call leg creation failure occurs while establishing a
CR/MCD call leg to a member of the FA group consisting of multiple
call destinations. This failure can occur due to a bad destination
being provided for that group member, such as may happen when the
phone number for that member is disconnected, or in other known
manners.
[0041] A calls the Flexible Alerting Pilot B. In this example, B is
a mobile connected to the CDMA wireless network. The call arrives
at B's home, or O-MSC 312 in the form of an ISUP IAM for B at 502.
The O-MSC 312 sends a LOCREQ invoke message to the HLR for B at
504.
[0042] The HLR for B 320 determines that B is a pilot for a
Flexible Alerting group, and retrieves information about the group
members at 506.
[0043] The HLR 320 responds to the O-MSC by sending a locreq
response at 508 that includes a Termination List including all of
the call legs for this Flexible Alerting call. The Termination List
in the locreq response includes 2 legs: one for a Local Termination
for B, since B is registered within radio contact at the O-MSC 312
in this example, and the other one for a PSTN termination for C,
another member of the Flexible Alerting group.
[0044] From parameters in the locreq response 508, the O-MSC 312
determines that this is a multi-leg call requiring it to set up
call legs to both B and C. So the O-MSC 312 offers the call to B by
sending a Page message to B at 510 to establish the call leg to B
in a known manner.
[0045] The O-MSC 312 also sends an IAM for C to the PSTN at 512
which includes C's number as the called party number to offer the
call to C.
[0046] At the Far End Switch responsible for connecting the call to
C, the switch determines that C has been disconnected and that the
call leg to C thus cannot be established at 512.
[0047] As a result, C's switch responds to the IAM of 512 with a
REL message (a disconnect message) at 518. The REL message includes
the cause of the CR/MCD call leg creation failure, indicating that
C has been disconnected.
[0048] The O-MSC 312, which is still waiting for the disposition
for all the call legs of this multi-leg call, gets the disconnect
message at 518, and detects that this error needs to be reported to
the HLR 320. The FA call continues with processing of the other FA
call legs made to other member(s) of the group in a manner which is
known in the art. The O-MSC 312 sends a Redirection Complaint to
the HLR 318 at 520, including the fact that this is for the
specific Flexible Alerting group owned by B, that the offending
member DN is C, and that the cause for the complaint/failure is
that C is disconnected.
[0049] The HLR 320 deactivates member C from this Flexible Alerting
group at 522. The HLR 320 also notifies the owner of this FA group
(B) that there is a bad member DN in the group at 522. The HLR 320
sends an SMS message to B's short message service center at 524 and
B is notified of the error via known SMS messaging at 528 in a
similar manner as described above.
[0050] FIG. 6 shows an example of the system 10 described above,
which is shown generally at 610, that includes an IMS
communications network elements as part of a telecommunications
network for performing Call Forwarding and/or Call Redirection in
accordance with the invention. The system 610 includes an IMS
Session Manager 612 functioning as the Detector 12 described above.
An IMS based Application Server 620 functions as the RNE 20
described above. C's End Office (EO) 618 functions as the Far End
Switch 18 described above. Also shown in FIG. 6 are Media Gateway
Control Function (MGCF) elements 650 for providing the circuit
trunk, such as those using ISUP signaling as shown at 660, to IP
interfaces which are known in the art. A Home Subscriber Server
(HSS) for B contains B's subscription information data including
call forwarding indicators and addresses to the destinations the
calls are to be forwarded to, such as C's address. Message Service
function blocks are shown for SMS messaging at 690, Voice Mail
messaging at 692, and E-mail messaging at 694.
[0051] FIG. 7 illustrates the call flow messaging sent between the
network elements of FIG. 6 for this Call Forwarding example. In the
example illustrated by FIGS. 6 and 7, calling party A calls called
party B. Called party B subscribes to Call Forwarding, as provided
by B's telecommunications Service Provider, so that calls made to
B's Directory Number are forwarded to C.
[0052] A calls B at 702 and A's EO 662 sends an ISUP IAM toward B's
home IMS at 704. The MGCF 650 converts the IAM to a SIP INVITE
message and sends it to the IMS Session Manager 612. The IMS
Session Manager 612 relays the INVITE message to B's AS 620 at 708.
The AS 620 queries the B's HSS-640 at 710 to get B's feature data
indicating what subscription features B subscribes to which can
affect the call. Since B currently has Call Forwarding active to C
as determined at 712, the HSS 640 sends B's feature data to the AS
620 indicating such. The AS 620 notes that forwarding to C is
active, adjusts the INVITE message accordingly by including C's
address as well as A's address therein, and sends it back to the
IMS Session Manager 612 at 716. The IMS 612 sends the INVITE toward
the appropriate MGCF 650 at 718. The MGCF 650 converts the INVITE
to an ISUP IAM and routes it toward C's EO 618 at 720.
[0053] The destination number for C has been recently been
disconnected, and no additional info is available. C's EO 618 sends
an ISUP RELease message backward, to the MGCF 650 which includes a
Cause Code parameter indicating that C was disconnected, thereby
providing the reason for the CR/MCD call leg creation failure. The
ISUP REL message itself indicates that the CR/MCD call leg creation
failure occurred.
[0054] The MGCF 650 converts the ISUP REL into a SIP 604 message
and sends to the IMS Session Manager at 726. The IMS Session
Manager 612 sends the 604 message to the AS 612 at 728. The AS
updates B's CF data in the HSS 640 at 730 to deactivate call
forwarding thereby functioning as the RNE 20 as described
above.
[0055] The HSS 640 acknowledges the change at 732. The AS 620 sends
notification to B at 734 that the forward-to number is bad via
Short message Service (SMS), and/or e-mail, and/or voice mail,
again functioning as the RNE 20 as described above.
[0056] The above description merely provides a disclosure of
particular embodiments of the invention and is not intended for the
purposes of limiting the same thereto. As such, the invention is
not limited to only the above-described embodiments. Rather, it is
recognized that one skilled in the art could conceive alternative
embodiments that fall within the scope of the invention.
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